'ytdownloader.py'
Using this script, you can download any youtube video simply by pasting the link. When you start the script, it will ask for your input as 'Link:'. You can paste the link and it will download the video for you. If you always want to download the highest resolution, you can simply comment out the lines where I have mentioned desired resolution and uncomment the lines where I mention highest resolution.
You can do so much more with this script. You can create options for users like enter 1 for 360p and enter 2 for 720p , this way.
Here is a youtube link for this script and how you can use this: https://youtu.be/2DOIUe8uFyI